Field of the Invention
The present invention relates to an organic light emitting diode (hereinafter, referred to as an “OLED”) display device and a method for fabricating the same.
Discussion of the Related Art
In recent years, OLED display devices are attracting considerable attention as flat panel display devices, which solve high weight and high volume, issues that are problems of cathode ray tubes (CRTs). Such an OLED display device includes an anode, a cathode, and an organic semiconductor layer formed between the anode and the cathode. The organic semiconductor layer includes a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer and an electron injection layer.
Meanwhile, microcavity technology is one method of improving color purity and brightness of OLED displays. Microcavity technology is an optical technology which employs microcavity effect wherein light emitted from the light-emitting layer mutually interferes between a complete-reflection surface and a semi-reflection surface. For this purpose, a conventional OLED display device is designed to have hole transport layers having different thicknesses in respective RGB sub-pixels. In this regard, hole transport layers for controlling thickness, which are separately stacked in order to control the thickness of hole transport layers in respective RGB sub-pixels, are produced at a high raw material cost, and remain on ribs of shadow masks and are bonded thereto upon formation of films due to material properties, thus causing a defect in which openings of shadow masks are clogged.